Thymus catharinae Camarda essential oil: ß-cyclodextrin inclusion complexes, evaluation of antimicrobial activity.

ABSTRACT

An efficient antimicrobial activity was evidenced in a complex ß-cyclodextrin-essential oil of Thymus catharinae Camarda (carvacrol chemotype). The release of carvacrol with respect to the antimicrobial activity was calculated as function of time. The ßCD-complex of the bioactive agent was obtained by a simple, efficient and non-expensive method without purification of the carvacrol chemotype essential oil. According to the starting stoichiometry of ß-cyclodextrin with respect to carvacrol, two inclusion complexes were produced, 11 and 21, respectively. The results demonstrate that, although the antimicrobial activity of the essential oil of T. catharinae Camarda is remarkable but acts too quickly in some types of application, its inclusion in a bio-matrix allows a slower release and improves its effectiveness.